Inorganic composition for inhibiting sap stain



Patented Aug. 8, i950 m asure coivrgg o roammerrmo STAIN Leslie-Rl'Bacon and mumsnbmmm, Wyan- I dotte, -Mich.,- as signors to Wyandotte Chemicals Gorpora-tion,.Wyandotte;.Mich., a corporation N Drawing. Application June. 9,1948, Serial No. 32,046

- #Tfi present invention relates to a chemical composition for preventing or: inhibiting sapstain and mold growth ingreen wood and lumber. Sap

stain, often times alternatively referred to as 6 Claims. (G1. 85)

be treated is th n dipped or immersed in such aqueous solution and after dipping, stacked in the customary mannerin the lumber yard and" snowed to "air dry for the usual period of three or four blue-stain, is a bluish or blue blackish discolo'rmonths. v,

fltidnwvithii'i the body ofthe wood. It isfcaused Exemplary formulations embodying the prinby the growth of fungi, one of the most prominent ciple orour invention areas follows: t

of which is the species C'e'rdtostomella pzlz'fem. v Sap stain is to be differentiated from mom growths which occur onthe ace of'the wood I by and which'vary widely in' coloi according to the mgmdlmts fiiiis characteristics of "the several organisms which f Basis may develop. g v H great many chemical coi'r'ipos ition'sfor inhib- Magnesium 'ili 0fli1crid i 5 65 v in gfefiqwood 'Bolaxorsodlnm Metaborate.. 3545 nave nerewrere been-de sed. However, inmost 1' cases it has been found thatsuch'compositions Compositions made I according to the above were not capable of inhibiting both sap stain and "stated formulation ranges'were made up and-submold growth. jected to the following test:

Such prior chemical compositions have been Test specimens of southern yellow pine in the based on both organic and inorganic chemicals, form of circular blocks transversely cut from the such as chlorophenolic compounds, organo-mersapwood of young trees were inoculated with a cury compounds and sodium alkaline salts such as viable culture of the fungus Cemtostomella pilisodium carbonate, sodium bicarbonate and borax. fem. Four of such specimen blocks were used Although the inorganic alkaline compounds have for each test composition. The test compositions been used as sap stain inhibitors for more than were made up into aqueous solutions in the conthe past forty years, they have been subject to centration as noted and applied to the fungusthe defect that they often stimulate rather than inoculated blocks. Blocks were then maintained retard surface mold growths. at a temperature of 82 F. and approximately We have discovered that inorganic sap stain 100% relative humidity for an incubation period compositions containing a sodium borate, such of five weeks. At the end of such five weeks as borax or sodium metaborate (i. e. sodium boperiod, the area of sapwood stained on both the rate in which the NazO/BzOa mol ratio lies within top and bottom surfaces of the four test blocks the range of 1 to 1'-2) and magnesium silicofluowas measured and the average thereof noted. As ride, overcome thisprevious defect, and quite to a control and for the purpose of comparison with the contrary of what might be expected, successa heretofore successful organic type of inorganic full prevent rather than stimulate surface mold chemical compound composition, the borax-modigrowths, as. well as effecting excellent sap stain lied soda-sodium pentachlorophenate composition control. I of U. S. Patent No. 2,392,987 was also employed The compositions of our invention are preferin the test series. Observations were made as to ably employed by being made up in an aqueous the degree of mold growth on the surface of the solution of 5-25 pounds of composition per 100 blocks. These test results are tabulated as folgallons of water. The green wood or lumber to lows:

Ingredients, Per ;121:1 1? $2 6153 Degree Compositions CeisitByweight, tratlon 1n sapwood of Mold olids Basis HQQ Stained Growth Solution Water Control No. 1 (Control)... Borax Modified Soda Sodium Pentachloropbe- 20 o. z gafisntrol) Same as above 1. 250 68. 1 Do.

d agnesium Silicofluoride 58.0.-.. 0. 863 0.0 Medium (61120). N E orax(NaaB4O-1.10HiO) 42.0. lviaznesium Silicofluoride 33.0 3.0 0.0 None sdiu m Metaborate 67.0

(NaBOrAHzO).

It will be noted that the ingredients in the exemplary test compositions in the foregoing table are in the hydrated form. Magnesium silicofluoride, borax and sodium metaborate, are most ordinarily available on the market as hydrated rather than anhydrous salts. Our invention however is equally well operable when one or more of the ingredients are employed in the anhydrous form. Thus, in the appended claims, the definition of the ingredients of the composition should be understood as including the hydrated and anhydrous forms as equivalents.

Equivalent modes of practicing our invention may be followed provided that they are within the scope and purview of the appended claims.

, We, therefore, distinctly claim and particularly point out as our invention:

1. A composition for inhibiting sap stain and mold growth in green wood comprising a mixture of magnesium silicofluoride and a sodium borate having an NazO/BzOa mol ratio of 1 to 1-2.

2. A composition for inhibiting sap stain and mold growth in green wood comprising a mixture of 2565% by weight magnesium silicofluoride 'of approximately 58% by weight magnesium silioofluoride and 42% borax,

4. A composition for inhibiting sap stain and mold growth in green wood comprising a mixture of approximately 33%. y weightmagnes'ium silicofiuoride and 67% sodium metaborate."

5. An aqueous solution bath for treating green wood to inhibit sap stain and mold growth comprising 5-25 pounds per gallons of water of the composition of claim 3.

6. An aqueous solution bath for treating green wood to inhibit sap stain and mold growth comprising 5-25 pounds per 100 gallons of water of the composition of claim 4.

LESLIE R. BACON. DWIGHT B. CONKLIN.

REFERENfiES CITED The following references are of record in the file of this patent:

UNITED STATES PA'IENTS OTHER REFERENCES 7 Lindgren, Prevention of Sap. Stain and Mold in Southern Woods by Chemical Treatment, reprint from Southern Lumberman, Nashvill Tenn, Feb. 1, 1931, page 2 of reprint. r 

1. A COMPOSITION FOR INHIBITING SAP STAIN AND MOLD GROWTH IN GREEN WOOD COMPRISING A MIXTURE OF MAGNESIUM SILICOFLUORIDE AND SODIUM BORATE HAVING AN NA2O/B2O3 MOL RATIO OF 1 TO 1-2. 